Competition - Coexistence

Question text:

Consider a pond where two species of phytoplankton (algae), A and B, live. Both species need phosphorus to grow, and there is not enough phosphorus in the pond for both species to grow indefinitely. Over time, species A and B both remained in the pond, with A more abundant than B (see graph). How would a biologist explain why this happened? (Note: neither species consumes the other species.)

Background information:

Under development

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This material is based upon work supported by the National Science Foundation (DUE grants: 1438739, 1323162, 1347740, 0736952 and 1022653). Any opinions, findings and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF.